Impact resistant door and method of manufacturing

ABSTRACT

A door comprising a frame having a hinge stile, a lock stile, a top rail, and a bottom rail defining an internal cavity, an interlayer secured within the internal cavity, a front skin further defining the internal cavity, and a rear skin opposite the front skin and further defining the internal cavity. A method of manufacturing a door including the steps of securing a hinge stile, a strike stile, a top rail, a bottom rail, and a first skin defining a frame and an internal cavity within the frame, inserting an interlayer within the internal cavity, securing the interlayer within the internal cavity to an inner surface of the frame with a plurality of fasteners, and securing a second skin opposite the first skin and further defining the internal cavity.

BACKGROUND OF THE INVENTION

1. Technical Field

The invention relates generally to an improved door and method of manufacturing. More particularly, the invention relates to an impact resistant door having an interlayer capable of withstanding flying debris. Specifically, the invention relates to a door with an interlayer having a woven structure disposed within an internal cavity.

2. Background Information

Doors provide homes with the ability to access the interior while providing security and restricting access as necessary. In hurricane prone areas of the world, doors must meet certain requirements in order to meet local safety standards. One of the more difficult standards to meet is the impact resistance requirement for flying debris that could be encountered. One of the common tests for flying debris is the typical large missile test. This test consists of firing a nine pound 2×4 piece of lumber with the end impacting the door at approximately 34 miles-per-hour. Ultimately, the door must prevent the 2×4 from passing through the door and potentially injuring the occupants.

Solid doors provide a great deal of impact resistance but suffer from a number or setbacks. First, solid doors are substantially more expensive than hollow doors because of the shear amount of material necessary. Second, solid doors are substantially heavier and more difficult to transport and mount in a doorway. Third, solid doors manufactured out of wood warp more easily and can require maintenance.

An alternative to solid doors are hollow doors. While hollow doors provide reduced costs and easier transportation and mounting, the hollow doors can be unsafe in areas where flying debris is a risk. Hollow doors generally include a pair of skins, or an inner and outer panel, attached to a central frame. The skins may be manufactured from a metal, wood, or a composite. Metal skins provide the necessary structure and impact resistance, but are generally unsatisfactory to consumers because of the fit and finish of metal. Specifically, metal is difficult to manipulate into a wood-like finish that most consumers desire in a door. Further, metal doors are subject to rusting and denting.

Wood and composite skins provide the desired appearance and finish of a solid door with the weight savings and other benefits of hollow doors. However, the is relative thinness of the skins leaves the home prone to flying debris.

SUMMARY OF THE INVENTION

The present invention broadly comprises a door including a frame having a hinge stile, a lock stile, a top rail, and a bottom rail defining an internal cavity, an interlayer secured within the internal cavity, a front skin further defining the internal cavity, and a rear skin opposite the front skin and further defining the internal cavity.

The present invention also broadly comprises a method of manufacturing a door including the steps of securing a hinge stile, a strike stile, a top rail, a bottom rail, and a first skin defining a frame and an internal cavity within the frame, inserting an interlayer within the internal cavity, securing the interlayer within the internal cavity to an inner surface of the frame with a plurality of fasteners, and securing a second skin opposite the first skin and further defining the internal cavity.

BRIEF DESCRIPTION OF THE DRAWINGS

The preferred embodiment of the invention, illustrative of the best modes in which Applicant has contemplated applying the principles of the invention, is set forth in the following description and is shown in the drawings.

FIG. 1 is a front elevation view of a home with a preferred embodiment impact resistant door;

FIG. 2 is a perspective view of a preferred embodiment impact resistant door;

FIG. 3 is an exploded view of a preferred embodiment impact resistant door;

FIG. 4 is a partial exploded view of a preferred embodiment impact resistant door with the interlayer and second skin separated from the frame and first skin;

FIG. 5 is a partial exploded view of the preferred embodiment impact resistant door with the interlayer secured within an internal cavity and the second skin being installed;

FIG. 6 is an enlarged perspective view of the preferred embodiment impact resistant door with portions in sections and broken away;

FIG. 7 is a perspective view of a preferred embodiment impact resistant door after installation of the second skin;

FIG. 8 is a cross-sectional view of the preferred embodiment impact resistant door taken generally along line 8-8 in FIG. 7 and foam being pumped into the internal cavity;

FIG. 9 is a cross-sectional view of the preferred embodiment impact resistant door taken generally along line 8-8 in FIG. 7 with a plug being inserted within a through hole to seal the internal cavity; and,

FIG. 10 is a cross-sectional view of a second preferred embodiment impact resistant door with the interlayer secured proximate a skin.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

At the outset, it should be appreciated that like drawing numbers on different drawing views identify identical, or functionally similar, structural elements of the invention. While the present invention is described with respect to what is presently considered to be the preferred embodiments, it is to be understood that the invention as claimed is not limited to the disclosed aspects.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs. Although any methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of the invention, the preferred methods, devices, and materials are now described.

The impact resistant door of the present invention is indicated generally at 12, as is particularly seen in FIGS. 1 through 10. Specifically, FIGS. 1 through 9 illustrate a first preferred embodiment impact resistant door 12, while FIG. 11 illustrates a second preferred embodiment impact resistant door 14. FIG. 1 illustrates door 12 mounted within a door threshold 16 of a house 18. Referring to FIG. 2, door 12 includes a top rail 20, a bottom rail 22 (not shown in FIG. 2), a hinge stile 24, and a lock stile (or strike stile) 26. Further, a front skin 28 is located opposite a rear skin 30 (not shown in FIG. 2).

FIG. 3 is an exploded view of a door 12, illustrating front skin 28 with an outer surface 32 and an inner surface 34. Rear skin 30 also includes an outer surface 36 and an inner surface 38. A frame 40 is composed of top rail 20, bottom rail 22, hinge stile 24, and lock stile 26. Frame 40 includes an internal cavity 42 defined by an inner surface 44 of frame 40. Specifically, top rail 20, bottom rail 22, hinge stile 24, and lock stile 26 each includes an inner surface 44 arranged proximate internal cavity 42. Further, front skin inner surface 34 and rear skin inner surface 38 define the two remaining boundaries of the internal cavity once the door is fully assembled.

Frame 40 is preferably assembled with an adhesive at the joints of the rails and stiles. For example, top rail 20 and bottom rail 22 may include an end joint 46 at each end arranged to receive the hinge stile or lock stile. The hinge and lock stiles are arranged to fit within end joints 46 with adhesive to form frame 40. Stiles 24 and 26 may also include a plurality of grooves 50 running the length of the stiles on both a front side 52 and a rear side 54. Grooves 50 receive adhesive used to mount the front and rear skins to frame 40, and may further receive a plurality of protrusions (not shown) extending from the inner surfaces of the front and rear skins.

In accordance with one of the main features of the present invention, an interlayer 56 is located between front skin 28 and rear skin 30. Interlayer 56 is preferably shaped and sized similar to frame 40 and specifically internal cavity 42. In a preferred embodiment, interlayer 56 is a woven material such as a fiberglass screen cloth, but may also include carbon fiber, Kevlar, or any other suitable material without departing from the spirit and scope of the present invention as claimed. As previously discussed, certain safety standards must be met in order for the doors to be sold in hurricane prone areas. For example, it has been found that an interlayer 56 of woven cloth fiberglass can provide sufficient strength to prevent penetration of a nine pound 2″×4″ piece of lumber impacting the door at 34 miles-per-hour.

FIGS. 4, 5, and 6 illustrate installation of interlayer 56 and the remaining components. FIG. 4 illustrates frame 40 already installed on rear skin 30 and interlayer 56 being installed in the direction associated with arrows 58, while FIG. 5 illustrates front skin 28 being installed in the direction associated with arrows 60.

Referring to FIG. 6 and in accordance with another main feature of the present invention, interlayer 56 is secured within internal cavity 42 by folding a perimeter 62 of the interlayer. Specifically, interlayer 56 is folded at a crease 64 along perimeter 62 and may be notched at a corner joint 66. Advantageously, folding interlayer 56 at crease 64 and corner joint 66 permits perimeter 62 to extend parallel to inner surface 44 and facilitate a secure connection between interlayer 56 and frame 40. Further, by folding interlayer 56 parallel to inner surface 44, fasteners 68 are installed through perimeter 62 and into inner surface 44 of frame 40. While fasteners 68 are shown as staples arranged approximately 2 inches from each other in the preferred embodiment, it is within the spirit and scope of the present invention as claimed to utilize any suitable fastener including, but not limited to, nails and adhesive.

FIGS. 7, 8, and 9 illustrate an assembled door 12 with the final steps of foam installation being performed. As particularly seen in FIG. 7, a through hole 70 extends through bottom rail 22 and communicates with internal cavity 42. After installing interlayer 56 and front skin 28, a pipe 72 is inserted within through hole 70 and foam 74 is forced into internal cavity 42 by a pump 76 in the direction associated with arrows 78. In a preferred embodiment, interlayer 56 is located at an equal distance from the front skin 28 and rear skin 30 so that foam 74 surrounds both sides of interlayer 56. FIG. 9 illustrates a cross-sectional view of the door after installing plug 80. Accordingly, door 12 can now be prepped for finishing, pre-hanging, and shipping.

Having described the structure of a first preferred embodiment, a second preferred embodiment will be described in detail and should be read in light of FIG. 10 in particular.

FIG. 10 illustrates impact resistant door 14 with internal structure similar to impact resistant door 12 with the exception of the placement of interlayer 56. In accordance with still another main feature of the present invention, interlayer 56 may be located in any position within internal cavity 42 without departing from the spirit and scope of the present invention so long as the interlayer extends for the entire length and width of the internal cavity. While FIG. 10 illustrates interlayer 56 located proximate rear skin 30, it is within the spirit and scope of the present invention as claimed to locate interlayer 56 proximate front skin 28 or in any position there between. Impact resistant door 14 also provides an ease of manufacturing advantage in that installation of foam 74 is simpler because it is not necessary to direct foam on both sides of interlayer 56.

Having described the structure of two preferred embodiments, a preferred method of manufacturing will be described in detail and should be read in light of FIGS. 1 through 10.

Initially, rear skin (or front skin if desired) is arranged with outer surface 36 facing down on an assembly table and an adhesive is applied to rear side 54 of top rail 20, bottom rail 22, hinge stile 24, and lock stile 26. Next, top rail 20, bottom rail 22, hinge stile 24, and lock stile 26 are fit together to form frame 40 and internal cavity 42 directly on inner surface 38 of rear skin 30. Interlayer 56 is draped within internal cavity 42 and maybe tensioned and fastened to inner surface 44 of frame 40 with a plurality of fasteners 68. Any excess interlayer is then trimmed away. A second layer of adhesive is applied to front side 52 of frame 40 and inner surface 34 of front skin 28 is secured to frame 40 along the adhesive. Door 12 is placed in a clamp press until the adhesive has cured. After trimming door 12 to its final width and height with a trim saw, the door is placed within a foam press where the door is pre-heated. A liquid foam, such as PUR foam is injected into internal cavity 42 via through hole 70. Plug 80 is inserted into through hole 70 and the foam is permitted to cure, at which point the impact resistant door is considered complete and may proceed through finishing and pre-hanging procedures well known in the art.

Accordingly, the impact resistant door is an effective, safe, inexpensive, and efficient device that achieves all the objectives of the invention, provides for eliminating difficulties encountered with prior art devices, and systems, and solves problems and obtains new results in the art.

In the foregoing description, certain terms have been used for brevity, clearness, and understanding; but no unnecessary limitations are to be implied therefrom beyond the requirement of the prior art, because such terms are used for descriptive purposes and are intended to be broadly construed.

Moreover, the description and illustration of the invention is by way of example, and the scope of the invention is not limited to the exact details shown or described.

Having now described the features, discoveries, and principles of the invention, the manner in which the impact resistant door is constructed and used, the characteristics of the construction, and the advantageous new and useful results obtained; the new and useful structures, devices, elements, arrangement, parts, combinations, and methods are set forth in the appended claims. 

1. A door comprising: a frame having a hinge stile, a lock stile, a top rail, and a bottom rail defining an internal cavity; an interlayer secured within the internal cavity; a front skin further defining the internal cavity; and, a rear skin opposite the front skin and further defining the internal cavity.
 2. The door of claim 1 wherein the interlayer is a woven swath of cloth.
 3. The door of claim 1 wherein the interlayer is one of a carbon fiber cloth, a Kevlar cloth, and a fiberglass cloth.
 4. The door of claim 1 wherein the interlayer is secured within the internal cavity with a plurality of fasteners.
 5. The door of claim 4 wherein the fasteners are staples.
 6. The door of claim 4 wherein the fasteners are spaced approximately two inches apart.
 7. The door of claim 4 wherein a perimeter of the interlayer is folded approximately parallel to an inner surface of the frame and the fasteners secure the perimeter to the inner surface of the frame.
 8. The door of claim 1 wherein the interlayer is secured at an equal distance between the front skin and the rear skin.
 9. The door of claim 1 wherein the interlayer is of sufficient strength to prevent penetration of a nine pound two inch by four inch piece of lumber impacting the door at 34 miles-per-hour.
 10. The door of claim 1 wherein the interlayer is secured proximate an inner surface of the front skin.
 11. The door of claim 1 wherein the interlayer is secured proximate an inner surface of the rear skin.
 12. The door of claim 1 further comprising a foam within the internal cavity and on at least one side of the interlayer.
 13. The door of claim 12 wherein the bottom rail further comprises a through hole and a plug, wherein the plug is removed to permit installation of the foam via the through hole, and the plug seals the internal cavity after installation of the foam.
 14. A method of manufacturing a door comprising the steps of: assembling a hinge stile, a strike stile, a top rail, a bottom rail, and a first skin defining a frame and an internal cavity within the frame; inserting an interlayer within the internal cavity; securing the interlayer within the internal cavity to an inner surface of the frame with a plurality of fasteners; and, securing a second skin opposite the first skin and further defining the internal cavity.
 15. The method of claim 14 further comprising the step of inserting a foam within the internal cavity.
 16. The method of claim 15 further comprising the step of inserting a plug within a through hole.
 17. The method of claim 14 further comprising the step of trimming a perimeter of the interlayer.
 18. The method of claim 14 further comprising the step of locating an adhesive on an inner surface of the first skin and the second skin.
 19. The method of claim 14 wherein the step of securing the interlayer includes the step of mounting the interlayer at an equal distance between the first skin and the second skin. 